Think About the Process Suppose the original quantity is 175 and the new quantity is 126. What expression represents the percent decrease? What is the percent decrease?
Which of these expressions represents the percent decrease?

i am sure it will be 90 degrees.

step-by-step explanation:

10000000000000000000000000000000

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4